Blinded by the Light
ou finally got it, that home with the marvelous view and the big, clear windows that take full advantage of it. But then the sun nears the horizon. Suddenly it’s “Lawrence of Arabia” time. The glare becomes razor blades aimed at your eyes. The room temperature soars. You can hear the furnishings wither around you.
Heat (from infrared and visible light), glare (from visible light) and ultraviolet rays come with the territory in Orange County.
While bountiful sunshine is one of the area’s most treasured resources, it also has to be respected for its destructive power.
“When the sun’s in front of you, you’re going to get a blast of radiation,” says George A. Loisos, architectural program coordinator at the PG&E; Energy Center in San Francisco.
“So many homes have so much window space. And not just homes looking out on the ocean. In Southern California it is something that has to be dealt with,” says David Atwood of D.W. Design in Laguna Niguel. “People want to have the shade down and still be able to see out. They also want the privacy at night.”
In decades past, designers used heavy drapes and windows with deep color tints to shut out the sun during the worst part of the day. These solutions were in tune with the interior design schemes of their day, but they defeated the purpose of having all that glass. And as time went on, scientific evidence began to suggest that these methods weren’t warding off sunlight’s more harmful effects.
Today, homeowners look for design solutions that are unobtrusive yet more effective. They want materials that filter out the dangerous ultraviolet light, keep the infrared and visible light from heating up the home’s interior and block the glare without interfering with the view.
They also want to keep room temperatures down--lowering cooling costs--and prevent ultraviolet light from fading fabrics, drying and cracking furniture and warping and shrinking wood floors.
The bad news is, there’s no single solution to the challenge. However, the home dweller can use low-tech and higher-tech solutions to fend off the bulk of the heat and glare while still being able to admire the scenery.
It depends on what homeowners want in the way of a view and what they will tolerate to have it.
An inland home with a dramatic westward view may benefit most from exterior shading that prevents the sun from hitting the windows, thereby reducing heat gain and lessening the need for air-conditioning.
The owner of a house on the coast might require less stringent measures for keeping cool but may want ways to cut down the glare from the ocean without interfering with the view.
Sunlight Control
For owners of homes under construction or homes undergoing major renovation, the most effective solutions to sunlight control are in space planning and the use of modern windows.
An architect can come up with appropriate window placements, particularly to the south and west, so that the sunlight isn’t coming directly through the windows.
Roof overhangs and deep windowsills can keep sun off the windows. Proper placement can keep heating, cooling and lighting costs down.
Homeowners not only have to consider the windows’ functionality, but also their aesthetic appeal and how they create a psychological link to the outside world.
Window manufacturers began working on more sophisticated windows in the mid-1970s, soon after the first energy crisis. Modern double-pane windows have a space between the panes where manufacturers can install coatings for solar control.
High-quality windows are available with “spectrally selective” tints and coatings. The tints reduce glare, while the coatings filter out solar heat while interfering very little with the visible light.
These windows can be “tuned” to block solar radiation in hot climates, or to allow solar radiation to pass through, helping to keep the home’s interior warm in cold climates.
The coatings and tints in a modern window can be very subtle; someone looking at the house from the outside would see little if any evidence of them.
Heat Reduction
For existing homes where owners aren’t tackling major renovations, glare and heat can suddenly become a problem when owners take down the old, heavy drapes. While they want protection from the sun, they don’t want to reprise bulky window treatments, which take up so much room, Atwood says.
A common solution in these cases is window tinting.
While glare is a major reason to want tinting, an effective film will also prevent solar heat gain--the difference in temperature created by sunlight hitting the window--thereby reducing cooling needs.
On a 70-degree day, with the sunlight coming directly at the window, the temperature near the glass might be 100, a 30-degree increase. If tinting reduces that by 50%, the temperature near the window would be only 85 degrees.
Today’s tinted films are better than the original versions created in the late ‘60s. Older window tints were little more than dyed plastic that simply blocked out some of the visible light, dimming the room in the process. They did little or nothing to cut the ultraviolet light, and they still allowed infrared light to heat the room.
Solis, a film by Southwall Technologies in Palo Alto, allows visible light while keeping out much heat.
Blocking UV Rays
Applied solar control films, also called adhesive backed films, cut glare and reduce the buildup of heat inside the house, and they block virtually all the UV light.
The major film manufacturers include 3M, Southwall Technologies and Courtaulds Performance Films. They offer a variety of tints in their films, though the most popular with homeowners is a neutral tint that is barely visible.
This clarity is a surprise to many people who still think of tinted window films as dark gray plastic that turns a house into a cave.
Cutting Glare
A popular film has been 3M’s Scotchtint. Holding the Scotchtint in your hand, you will see a light gray tint. On the window and back lit, it’s neutral, says Charles Payne of Sundown Window Tinting in Irvine.
Such films cut the visible light by 50% to 60%.
While this will reduce the glare, it may not be enough. Glare is bright light in the visible spectrum. Cutting glare means putting something between you and the sun. That something could be a wall or a pane of dark glass.
“Reducing glare is not [done with] a lighter, clearer film,” says Bob Niger of 3M Construction Markets.
Films such as Scotchtint and Solis are applied to the inside of the window. The coating that reflects the ultraviolet light and the infrared light is nearest the window, and then there is a scratch-resistant coating on the room-side surface. “It’s like hanging wallpaper, except it’s on glass,” says Dennis Dillard of Southwall Technologies.
Most modern solar control films cost about $7 a square foot, installed, and will last five to 15 years depending on the quality of the film and its application, and on the environment in which it is operating, according to PG&E.;
While window films can eliminate infrared light without reducing visibility, the visible light will still heat up a room, Loisos says.
Interior Treatments
Interior designer Elaine Hankin of Huntington Beach recommends tinting windows to preserve the view, but she also suggests building the home with wide eaves, using awnings or putting in trees to help the situation. Trees can be useful in blocking light from a side window.
“People who live near the beach and have an ocean view don’t want window coverings,” Hankin says. “They’ll use draperies or pleated shades that don’t obstruct the view.”
Interior window treatments include 2-inch wood blinds such as those manufactured by Kirsch or Empire Window, matchstick blinds and Roman shades.
There are dynamic liquid crystal systems that serve as curtains, Loisos says. In the next five years, he says, we can expect to see “smart windows” that can change from clear to reflective when a mild electric current is passed through them. These electrochromic windows are made up of a semiconductor sandwiched between two layers of glass.
The electrochromic windows will not be an inexpensive solution. While a thermal pane window will cost $5 to $7 a square foot, an electrochromic window may cost $40 to $100 per square foot, Loisos estimates.
